CopperTop is best suited when you need reliable, long lasting life from your everyday devices like toys, portable tape and CD players, clocks and radios, remote controls, electronic games, smoke alarms, PDA's, flashlights and much more.
What can I say about batteries? It would be nice to have larger quantity packs.
Duracell batteries are pretty much Duracell batteries. I did not compare them with other batteries for longevity or price wise.